I’ll take a look. I’ve used some of those purpose built tools before and I was never much of a fan. Usually due to how the furniture was handled.
Back in high school I had extensive experience with AutoCAD R14 (3 years with it, after 2 years of board drafting), and then in college I had some more experience with a couple other packages. But this was all a couple decades ago now.
Your CAD experience level sounds like it is similar, but a bit higher than mine (2 years hand drawing, 2 years CAD, some more hobbyistic CAD & 3D modelling over the years for personal projects), so yeah SweetHome3D might not be that much help for you over using some CAD software directly.
I found furniture handling OK, but certainly has its rough edges. Good thing is that one can just import 3d models and so create the relevant pieces of furniture themselves; or use the generic boxes that SH3D has, if it's just for 2d space usage.
I did a few office space modellings with it, i.e. to get a feeling of how the space could be used best, and for that I found it quite OK. The result I got compared to the time invested was pretty good for my taste.
Back in high school I had extensive experience with AutoCAD R14 (3 years with it, after 2 years of board drafting), and then in college I had some more experience with a couple other packages. But this was all a couple decades ago now.